Flexible pipe section and coupling therefor



J. A. ZUBLIN Filed NOV. 5, 1944 June 11, 1946.

FLEXIBLE PIPE SECTION AND COUPLING THEREFOR Patented June il, 1946 FLEmBLE PIPE SECTION AND COUPLING THEREFOR l John A. Zublln, Los Angeles, Calif. Application November 3, 1944, Serial No. 561,732

3 Claims.

relates to an improved coupling therefor, pridrill string for drilling The present invention iiexible pipe section and marily adapted for use in wells.

A procedure and apparatus for drilling lateral bores deviating from existing well bores are disclosed in U. S. Patent No. 2,336,338, heretofore issued to me. It has been found highly desirable in the drilling of lateral bores to employ a turbine driven bit, such for example as disclosed in U. S. Patent No. 2,336,336, carried at the lower end of the drill string. It is likewise expedient to drive the turbine at high speeds, necessitating the employment of liquid pressures varying, for exam ple, between 200 and 1,000 pounds per square inch in the flexibletubular drill string.

In order to carry the high pressure iiuid medium for actuating the turbine, lubricatingv the bit, and carrying the detritus, it is necessary to provide an imperforate exible lining within the resilient flexible metal tube, as well as. appropriate couple means for interconnecting separate pipe sections. y

It is a primary objectv of the present invention to provide an improved ilexible pipe section and coupling therefor, which will preclude leakage of the high pressure iiuid from the drill string.

It is a more specic object of the invention to provide a flexible pipe section embracing an imperirate exible lining secured to the resilient flexible metal tube adjacent the ends thereof, over an area. adequate to create an effective hermetic seal. f y

It is a further and more invention to provide complementa] coupling members, one adapted to be carried at each end of the exible pipe section for interconnecting the exible pipe section to other-sections of a drill string, and to employ the complemental coupling members to further ensure an eiective hermetic seal between the resilient exible metal tube and the flexible lining therefor.

Other and more specific objects of the invention will appear in the course of the following description, in which reference will be made to the accompanying drawing forming a part hereof and in which:

Fig. i is a side-elevational view of a exible pipe section and coupling therefor conforming to the invention;

Fig. 2 is an. enlarged cross-sectional view through the ends ci adjacent exible pipe sections showins the complemental coupling members employed to interconnect such sections; and

Fig.- 3'is a detailed viewvof specic object of the a means taken on the line 3-3 of Fig. 2'showing one of the rivets removed and another prior to` peening.

Referring to Fig. l, the resilient ilexible metal tube of the flexible pipeA section is indicated generally by the reference numeral I. In this embodiment a helical slot 2 vextends from a point 3 somewhat removed from the end B of the resilient iiexible tube l to a point 5 somewhat removed from the opposite end 6 of the tube I.

It win be understood that the slotted tube is' both exible and resilient, and is adapted to'partake of vconsiderable curvature in use.

An imperiorate lining in the form of a hose 'l l0, Well within the end 6 of the metal tube I.

The metal tube l is internally threaded at each end as indicated at Il, and the threads II extend well into the inner end of the metal tube I to the point I2, 'so that the ends of the exible hose 'I overlap a substantial portion of the internally threaded area ofthe tube I at each end thereof. It is through this overlapping area of the threaded portion of the metal tube I and the ilexible hose that the same are interlocked to provide an eiiective hermetic seal. A

The interlocking is accomplished in the exempliied embodiment through the medium of two rows of staggered large headed rivets I3. The large heads of these rivets I4 are positioned on the inside of the exible hose 1 and the Shanks 'of the rivets extend through the exible hose 'l into` the countersunk openings 26 in the metal tube l, into which the free ends peened, while the heads I4 thereof are forced outwardly under tremendous pressure by a suit.- able slightly tapered mandrel. The riveting operation causes the internal threads II of the tube l to embed themselves in theouter wall of the hose l. The large staggered heads I4 of the rivets I3 substantially completely cover the major portion of the overlapping area between the exible hose 7 and the metal tube I, and eil'ectively interlock the iiexible hose 1 and the metal tube I throughout an area adequate to ensure an effective hermetic seal (see Fig. 3)

To further augment the eil'ective hermetic seal I the interlocking 55'. between the nexible hose 1 and the metal tube l,

of the rivets are y '3 l are .beveled as shown at I5, and are adapted'to be expanded at the extreme end into contact with the tube l by the complemental bevel it of each. of the complemental coupling members il and I8. The female coupling member il is externally threaded at i9 and is adapted to be` received by the internal threads i l in that portion of the interiorly threaded end of the metal tube i, which does not overlap with the flexible hose l. When the female coupling l1 is tightened of the metal tube i, the bevel portion it thereof is adapted to contact the bevel portion i5 of the ilexible hose l! and, as above described, expand the same into tight contact with'the metal tube l.

vTo further ensure the provision of a hermetic seal between the metal pling member il, an annular groove 2B between these elements may be provided which can be conveniently filled with a circular welded ring 2 i. The female couplingmember il is internally threadedv at 22 to receive the complemental threaded portion 23 of the male coupling i8, which is also threaded at 2d to be received in the end of a second resilient metal tube 25, in all respects the same as the metal tube i.

It will be appreciated that the flexible hose i is interlocked to the metal tube l at the end thereof, in the same manner as above described with respect at the end E tion that at a complemental male all respects the same as theshown in Fig.' 2.

From the foregoing, it will be noted that the invention provides a hermetic seal between the flexible rubber hose and metal tube, which doeg not reduce the internal diameter of the hose, nor increase the outside diameter of the metal tube. It will additionally the ends of the hose the end d the flexible tube i receives member of the coupling, in male member' i6 be noted that the invention provides a coupling between the flexible pipe section which is not cured to the rubber of the rubber hose, and which when in position in a drillstring lies flush with both the outside diameterof the flexible pipesecinto position in the end' to the interlocking of these elementsv of the tube i, with the single excep- Having thus described my invention what I v claim is:

tube l and the female couthe resilient flexible members of a pipe 1. A flexible pipe section comprising a resilient metal tube slotted intermediate its ends to impart flexibility thereto, an imperforate flexible lining within said tube vbridging the slotted portion thereof, interlocking elements extending through said lining and tube over an area adequate to create a hermetic seal adjacent each end thereof.

2. A flexible pipe section comprising a resilient metal tube slotted intermediate its ends to impart flexibility thereto, lining within said tube tion thereof, interlocking elements extending through said lining and tube over an area, adequate to create a hermetic seal adjacent each end thereof, said metal tube extending at its ends beyond said flexiblelining, said extensions being internally threaded to receive complemental members of a pipe coupling.l

3. A exible pipe section comprising a resilient metal tube slotted intermediate its ends t0 impart flexibility thereto, an',imperforate flexible lining within said tube bridging the slotted portion thereof, interlocking elements extending through said lining and tube over an area adequate to create a hermetic seal adjacent each end thereof, said metal tube extending at its ends beyond'said flexible lining, said extensions being internally threaded to receive complemental member of the pipe coupling mounted in the threaded extension at each endv of said metal tube, the inner ends of said complemental coupling members serving to yexpand the free ends of said imperforate flexible lining into liquidtight contact with the interior wall of said resillent metal tube.

. JOHN A. ZUBLIN.

of the nenne im-l an imperforate flexiblev bridging the slotted porcoupling, a complementalv 

